From "The Sacrament of the Body and Blood of Christ--Against the Fanatics". 1526.
Here then you have the distinction as to what the commemoration is, and how one should use the sacrament and derive benefit from it, namely, by simply correcting our shortcomings and failings. We share the common frailties of other people, and each has his own peculiar frailties; because of these we come here to seek strength. This is why this sacrament is called a food for hungry and thirsty souls, who feel their misery and would gladly be rescued from death and all misfortune. The papists have taught: "Beware, do not go thither unless you are pure and have no evil conscience," so that Christ may be certain to have a pure abode. They have so stupefied and frightened the poor souls by this that they have fled from the sacraments, and yet have had to receive it under constraint--with such trembling that they would as gladly have entered a fiery furnace.
We are to be pure in the sense that we are sorry for our sins and would gladly be rid of them, and are vexed that we are such miserable people--insofar as we are serious about it and not just pretending. Complete sinlessness, however, no one will ever attain. Even if you should do so, you would not dare to go to the sacrament, for it was instituted specifically for the sake of the weak. So much for the use of the sacrament: it is to strengthen the conscience against all distress and temptation.
Now there remains the part concerning the fruit of the sacrament. Of this I have had much to say at other places. It is nothing other than love. The early fathers too have emphasized this most of all, and for this reason they called the sacrament communio, that is, a communion. this is also presented to us here in two ways--first, by way of an example, and second, by way of a symbol or sign which is the bread and wine--so every Christian, no matter how crude he maybe, may be able to comprehend here in the sacrament the whole christian doctrine, what he is to believe and what he is to do through faith. for it is necessary for each one to know that Christ has given his body, flesh, and blood on the cross to be our treasure and to help us to receive forgiveness of sins, that is, that we may be saved, redeemed from death and hell.
That is the first principle of christian doctrine. It is presented to us in the words, and his body and blood are given to us to be received corporeally as a token and confirmation of this fact. to be sure, he did this only once, carrying it out and achieving it on the cross; but he causes it each day anew to be set before us, distributed and poured out through preaching, and he orders us to remember him always and never forget him.
The second principle is love. It is demonstrated in the first place by the fact that he has left us an example. As he give himself for us with his body and blood in order to redeem us from all misery, so we too are to give ourselves with might and main for our neighbor. whoever knows this and lives accordingly is holy, and has not much more to learn, nor will he find anything more in the whole bible. for these two principles are here inscribed together as on a tablet which is always before our eyes and which we use daily.
(Lull, pp. 330, 331)